Quantum fingerprinting for heterogeneous devices localization

In this paper, we present QHFP, a device-independent quantum fingerprint matching algorithm that addresses two of the issues for realizing worldwide ubiquitous large-scale location tracking systems: scalability of storage space and running time as well as devices heterogeneity. In particular, we present a quantum algorithm with a complexity that is exponentially better than the classical techniques, both in space and running time. QHFP also has provisions for handling the inherent localization error due to building the large-scale fingerprint using heterogeneous devices. We give the details of the entire system starting from extracting device-independent features from the raw received signal strength, mapping the classical feature vectors to their quantum counterparts, and showing a quantum cosine similarity algorithm for fingerprint matching. We implement our quantum algorithm and deploy it in a real testbed using the IBM Quantum machine simulator. We also study the effect of the different quantum error sources, such as quantum gates error and quantum measurement error, on the system accuracy. Based on this, we discuss the suitable provisions to mitigate the effect of the quantum error sources on the localization accuracy. Results confirm the ability of QHFP to obtain the correct estimated location with an exponential improvement in space and running time compared to the traditional classical counterparts. In addition, the proposed device-independent features lead to more than 20% better accuracy in median error. This highlights the promise of our algorithm for future ubiquitous large-scale worldwide device-independent fingerprinting localization systems.